A Gas‐Sensitive SPIM Sensor for Detection of Ethanol Using SnO₂ as Sensing Element

Abstract

In this study, a gas‐sensitive scanning photo‐induced impedance microscopy (SPIM) sensor using tin dioxide (SnO2) as sensing element is proposed, which detects the local impedance change on the sensor surface in response to ethanol vapor. The impedance change of the SnO2 film is detected by monitoring the AC photocurrent signal induced by a laser beam. This measurement can be done in a spatially resolved manner by using a scanning laser beam and two‐dimensional maps are obtained thanks to the light‐addressability of SPIM. This technique is expected to be applied to the visualization of gas distributions on the sensing surface.